Pseudocoleodictyospora sukhothaiensis Doilom, D.J. Bhat & K.D. Hyde, sp. nov., Index Fungorum number: IF551968
Etymology: from the Latin –ensis, referring to an association with Sukhothai, the place of collection.
Holotype: MFLU 15–3530
Saprobic on bark of living T. grandis. Sexual morph: Undetermined. Asexual morph: Colonies on natural substrate, punctiform, sporodochial, gregarious, scattered, numerous, black. Hyphae pale brown to brown, septate, slightly constricted at the septa. Conidiophores up to 13 μm long, 1.5–4 wide, micronematous, erect to slightly curved, constricted at the septa, arising from prostrate, loose hyphae. Conidiogenous cells blastic, integrated, terminal, determinate. Conidia (20–)40–45(−56) × (19–)27–30(−35) μm (x = 40 × 27μm, n = 50), dictyosporous, bulbil-like, muriform, initially pale brown, becoming brown to dark brown, horizontal on conidiogenous cell, very variable in size and shape; globose to ellipsoidal to irregular with a protruding basal cell.
Culture characteristics: Conidia germinating on PDA with in 24 h. Germ tubes produced around the conidia. Colonies on MEA reaching 11–13 mm diam. after 7 days in the dark at 25 °C (x = 12 mm, n= 5), edge entire, velvety, medium dense, flat or effuse at the edge, low convex at the old mycelium plugs, aerial, brownish grey (7F2) from both above and below.
Habitat: Known to inhabit bark of living T. grandis (current study).
Known distribution: Thailand (current study).
Material examined: THAILAND, Sukhothai Province, Sirimas District, on bark of living T. grandis, 3 August 2012, S. Hongsanan, (MFLU 15–3530, holotype), ex-type living culture MFLUCC 12–0554, MKT 070, ICMP 21164, GenBank Accession No: ITS: KU712440, LSU: KU764710, RPB2: KU712493, SSU: KU712471.
Notes: Phylogenetic analyses separate Ps. sukhothaiensis from Ps. tectonae and Ps. thailandica (Fig. 9). Polymorphic nucleotide comparisons (Table 6) also indicate that Ps. tectonae and Ps. thailandica are different (see DNA phylogeny result). Pseudocoleodictyospora sukhothaiensis is introduced here as a novel species based on its conidia being shorter and narrower than Ps. tectonae and also longer and wider than Ps. thailandica (Table 7).
FIG Pseudocoleodictyospora sukhothaiensis (MFLU 15–3530, holotype). a, b Conidia on host surface. c Mycelia on host. d–i Hyphae and conidia with basal cell (arrows). j, k Conidia on conidiophores. l Colony on MEA after 7 days (above and below views). m Culture on PDA after 5 days from single spore isolation. Notes: c, e–i Stained in lactophenol cotton blue. Scale bars: a, b = 200 μm, c–i, k = 20 μm, j = 10 μm